The most lightweight jQuery solution for a fixed scroll-page-to-top icon, plus nice effects.

Smooth fade effect when activate or deactivate the go-top icon.
Normal and hover images for the go-top icon.
Custom tooltip compatible with the [rz] Tooltip extension.
Selectable positions and offsets fine-tunning.
Selectable 3D push effects on click.
Set up how many scrolled down pixels are required to activate the go-top icon.
Easing effects.
Time control.
Set up the maximum that can scroll to top (top offset!).
Multi-instance: icons can appear at both right and left sides! (or at the all four corners!)